From 67a9a189511dec61a774ea97c2f9b30ea0a6d8b3 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 9 Apr 2021 09:35:12 +0200 Subject: [PATCH] tty: clarify that not all ttys have a class device Commit cb419364fd17 ("tty: add tty_struct->dev pointer to corresponding device instance") added a struct device pointer field to struct tty_struct which was populated with the corresponding tty class device during initialisation. Unfortunately, not all ttys have a class device (e.g. pseudoterminals and serdev) in which case the device pointer will be set to NULL, something which have bit driver authors over the years. In retrospect perhaps this field should never have been added, but let's at least document the current behaviour. Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20210409073512.6876-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- include/linux/tty.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/tty.h b/include/linux/tty.h index 51f56e5ec955b..a228c0ee484f2 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -284,7 +284,7 @@ struct tty_operations; struct tty_struct { int magic; struct kref kref; - struct device *dev; + struct device *dev; /* class device or NULL (e.g. ptys, serdev) */ struct tty_driver *driver; const struct tty_operations *ops; int index; -- 2.39.5